Steven C. Zimmerman

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Name: Zimmerman, Steven C.
Organization: University of Illinois at Urbana?Champaign , USA
Department: Department of Chemistry
Title: (PhD)

TOPICS

Co-reporter:Hsuan-Chin Wang, Joshua M. Grolman, Aoon Rizvi, Grant S. Hisao, Chad M. Rienstra, and Steven C. Zimmerman
ACS Macro Letters March 21, 2017 Volume 6(Issue 3) pp:321-321
Publication Date(Web):March 10, 2017
DOI:10.1021/acsmacrolett.6b00968
The majority of current pH-triggered release systems is designed to respond to either low or high pH. Encapsulants based on polyampholytes are an example of materials that can respond to both acidic and basic pH. However, polyampholyte-based encapsulants generally possess a low loading capacity and have difficulty retaining their small-molecule cargo. The current work utilizes interfacial polymerization between polyamines and a pyromellitic diester diacid chloride to form high capacity “liquid core–shell” polyamide microcapsules that are stable in a dry or nonpolar environment but undergo steady, controlled release at pH 7.4 and accelerated release at pH 5 and pH 10. The rate of release can be tuned by adjusting the amine cross-linker feed ratio, which varies the degree of cross-linking in the polymer shell. The thin-shell microcapsule exhibited suitable barrier properties and tunable dual acid/base-triggered release, with applications in a wide range of pH environments.
Co-reporter:Hang Xing, Yugang Bai, Yunhao Bai, Li Huey Tan, Jing Tao, Benjamin Pedretti, Gretchen A. Vincil, Yi Lu, and Steven C. Zimmerman
Journal of the American Chemical Society March 15, 2017 Volume 139(Issue 10) pp:3623-3623
Publication Date(Web):March 6, 2017
DOI:10.1021/jacs.7b00065
We describe the preparation of cross-linked, polymeric organic nanoparticles (ONPs) with a single, covalently linked DNA strand. The structure and functionalities of the ONPs are controlled by the synthesis of their parent linear block copolymers that provide monovalency, fluorescence and narrow size distribution. The ONP can also guide the deposition of chloroaurate ions allowing gold nanoparticles (AuNPs) to be prepared using the ONPs as templates. The DNA strand on AuNPs is shown to preserve its functions.
Co-reporter:Cartney E. Smith, JuYeon Lee, Yongbeom Seo, Nicholas ClayJooyeon Park, Artem Shkumatov, Dawn Ernenwein, Mei-Hsiu Lai, Sanjay MisraCharles E. Sing, Brenda Andrade, Steven C. ZimmermanHyunjoon Kong
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 2) pp:
Publication Date(Web):December 19, 2016
DOI:10.1021/acsami.6b10891
Nanosized bioprobes that can highlight diseased tissue can be powerful diagnostic tools. However, a major unmet need is a tool with adequate adhesive properties and contrast-to-dose ratio. To this end, this study demonstrates that targeted superparamagnetic nanoprobes engineered to present a worm-like shape and hydrophilic packaging enhance both adhesion efficiency to target substrates and magnetic resonance (MR) sensitivity. These nanoprobes were prepared by the controlled self-assembly of superparamagnetic iron oxide nanoparticles (SPIONs) into worm-like superstructures using glycogen-like amphiphilic hyperbranched polyglycerols functionalized with peptides capable of binding to defective vasculature. The resulting worm-like SPION clusters presented binding affinity to the target substrate 10-fold higher than that of spherical ones and T2 molar MR relaxivity 3.5-fold higher than that of conventional, single SPIONs. The design principles discovered for these nanoprobes should be applicable to a range of other diseases where improved diagnostics are needed.Keywords: hyperbranched polyglycerol; magnetic resonance imaging; nonspherical nanoparticle cluster; superparamagnetic iron oxide nanoparticle; targeted imaging;
Co-reporter:Yugang Bai, Xinxin Feng, Hang Xing, Yanhua Xu, Boo Kyung Kim, Noman Baig, Tianhui Zhou, Andrew A. Gewirth, Yi Lu, Eric Oldfield, and Steven C. Zimmerman
Journal of the American Chemical Society 2016 Volume 138(Issue 35) pp:11077-11080
Publication Date(Web):August 16, 2016
DOI:10.1021/jacs.6b04477
We show that copper-containing metal–organic nanoparticles (MONPs) are readily synthesized via Cu(II)-mediated intramolecular cross-linking of aspartate-containing polyolefins in water. In situ reduction with sodium ascorbate yields Cu(I)-containing MONPs that serve as highly efficient supramolecular catalysts for alkyne–azide “click chemistry” reactions, yielding the desired 1,4-adducts at low parts per million catalyst levels. The nanoparticles have low toxicity and low metal loadings, making them convenient, green catalysts for alkyne–azide “click” reactions in water. The Cu-MONPs enter cells and perform efficient, biocompatible click chemistry, thus acting as intracellular nanoscale molecular synthesizers.
Co-reporter:Yugang Bai; Lien Nguyen; Ziyuan Song; Shaohong Peng; JuYeon Lee; Nan Zheng; Iti Kapoor; Lauren D. Hagler; Kaimin Cai; Jianjun Cheng; H. Y. Edwin Chan
Journal of the American Chemical Society 2016 Volume 138(Issue 30) pp:9498-9507
Publication Date(Web):June 29, 2016
DOI:10.1021/jacs.6b03697
The construction of a multivalent ligand is an effective way to increase affinity and selectivity toward biomolecular targets with multiple-ligand binding sites. Adopting this strategy, we used a known cell-penetrating peptide (CPP) mimic as a scaffold to develop a series of multivalent ligand constructs that bind to the expanded dCTG (CTGexp) and rCUG nucleotide repeats (CUGexp) known to cause myotonic dystrophy type I (DM1), an incurable neuromuscular disease. By assembling this polyvalent construct, the hydrophobic ligands are solubilized and delivered into cell nuclei, and their enhanced binding affinity leads to the inhibition of ribonuclear foci formation and a reversal of splicing defects, all at low concentrations. Some of the multivalent ligands are shown to inhibit selectively the in vitro transcription of (CTG·CAG)74, to reduce the concentration of the toxic CUG RNA in DM1 model cells, and to show phenotypic improvement in vivo in a Drosophila model of DM1. This strategy may be useful in drug design for other trinucleotide repeat disorders and more broadly for intracellular multivalent targeting.
Co-reporter:Ying Li, Yugang Bai, Nan Zheng, Yang Liu, Gretchen A. Vincil, Benjamin J. Pedretti, Jianjun Cheng and Steven C. Zimmerman  
Chemical Communications 2016 vol. 52(Issue 19) pp:3781-3784
Publication Date(Web):01 Feb 2016
DOI:10.1039/C5CC09430E
Fluorescent, aqueous-soluble, crosslinked dendronized polyols (CDPs) are obtained through a sequential process involving ring-opening metathesis polymerization (ROMP), intra-chain ring-closing metathesis (RCM), and hydrolysis. This general strategy improves the quantum yields (QYs), brightness, and photostability of five common fluorophores whose emission wavelengths cover 150 nm. Additionally, the availability of the polymeric fluorophore to the cytosomes opens the door to applications in bioimaging and intracellular delivery.
Co-reporter:Ying Li; Edmund C. M. Tse; Christopher J. Barile; Andrew A. Gewirth
Journal of the American Chemical Society 2015 Volume 137(Issue 44) pp:14059-14062
Publication Date(Web):October 29, 2015
DOI:10.1021/jacs.5b10016
To control proton delivery across biological membranes, we synthesized a photoresponsive molecular switch and incorporated it in a lipid layer. This proton gate was reversibly activated with 390 nm light (Z-isomer) and then deactivated by 360 nm irradiation (E-isomer). In a lipid layer this stimuli responsive proton gate allowed the regulation of proton flux with irradiation to a lipid-buried O2 reduction electrocatalyst. Thus, the catalyst was turned on and off with the E-to-Z interconversion. This light-induced membrane proton delivery system may be useful in developing any functional device that performs proton-coupled electron-transfer reactions.
Co-reporter:Lien Nguyen; Long M. Luu; Shaohong Peng; Julio F. Serrano; H. Y. Edwin Chan
Journal of the American Chemical Society 2015 Volume 137(Issue 44) pp:14180-14189
Publication Date(Web):October 16, 2015
DOI:10.1021/jacs.5b09266
Single-agent, single-target therapeutic approaches are often limited by a complex disease pathobiology. We report rationally designed, multi-target agents for myotonic dystrophy type 1 (DM1). DM1 originates in an abnormal expansion of CTG repeats (CTGexp) in the DMPK gene. The resultant expanded CUG transcript (CUGexp) identified as a toxic agent sequesters important proteins, such as muscleblind-like proteins (MBNL), undergoes repeat-associated non-ATG (RAN) translation, and potentially causes microRNA dysregulation. We report rationally designed small molecules that target the DM1 pathobiology in vitro in three distinct ways by acting simultaneously as transcription inhibitors, by inhibiting aberrant protein binding to the toxic RNA, and by acting as RNase mimics to degrade the toxic RNA. In vitro, the agents are shown to (1) bind CTGexp and inhibit formation of the CUGexp transcript, (2) bind CUGexp and inhibit sequestration of MBNL1, and (3) cleave CUGexp in an RNase-like manner. The most potent compounds are capable of reducing the levels of CUGexp in DM1 model cells, and one reverses two separate CUGexp-induced phenotypes in a DM1 Drosophila model.
Co-reporter:Dawn Ernenwein;Ariane M. Vartanian
Macromolecular Chemistry and Physics 2015 Volume 216( Issue 16) pp:1729-1736
Publication Date(Web):
DOI:10.1002/macp.201500159
Co-reporter:Yugang Bai, Hang Xing, Peiwen Wu, Xinxin Feng, Kevin Hwang, Jennifer M. Lee, Xin Yi Phang, Yi Lu, and Steven C. Zimmerman
ACS Nano 2015 Volume 9(Issue 10) pp:10227
Publication Date(Web):September 1, 2015
DOI:10.1021/acsnano.5b03909
The functional groups displayed on the surface of nanoparticles (NP) are known to play an important role in NP cellular uptake. However, only a few systematic studies have been reported to address their role, in large part because of the difficulty in regularly varying the number and structure of the functional groups on the NP surface. We employ a bottom-up strategy for the synthesis of water-soluble organic nanoparticles (ONPs) with different sizes and functional groups, using readily available monomers. Utilizing flow cytometry, we measured the HeLa cell uptake efficiency of ONPs that contain side-chains with a different (a) length, (b) number of hydroxyl groups, and (c) number of methyl groups. We have also investigated ONPs with the same functional groups but different sizes. The potential formation and influence of protein corona was examined using the same approach but in the presence of serum. The results demonstrate that under both serum and serum-free conditions the surface-exposed functional groups determine the efficiency of cellular uptake of the particles, and that the trend can be partially predicted by the lipophilicity of the polymeric ONP’s repeating units. Also, by using a “masking” strategy, these particles’ cellular uptake behavior could be altered conveniently.Keywords: cellular uptake; lipophilicity; organic nanoparticle; surface functional groups;
Co-reporter:Si Kyung Yang and Steven C. Zimmerman
Macromolecules 2015 Volume 48(Issue 8) pp:2504-2508
Publication Date(Web):April 17, 2015
DOI:10.1021/acs.macromol.5b00164
The synthesis of a water-soluble polyglycerol dendrimer with two orthogonal functional groups at the core is reported. The two groups, an azide and amine group, are highly reactive toward alkyne and activated ester moieties, respectively. The orthogonality of the two chemical reactions is demonstrated by the ability to conjugate quantitatively either group, independent of the other and in either order. The orthogonal functionalization of the azide- and amine-cored dendrimer can be accomplished in a stepwise or a one-pot synthetic protocol. All resulting bifunctional dendrimers are fully soluble in water as the water-soluble dendritic scaffold decorated with 48 hydroxyl groups on the surface successfully solubilizes both the hydrophobic fluorophore and targeting group.
Co-reporter:Chun-Ho Wong ; Lien Nguyen ; Jessie Peh ; Long M. Luu ; Jeannette S. Sanchez ; Stacie L. Richardson ; Tiziano Tuccinardi ||; Ho Tsoi ; Wood Yee Chan ; H. Y. Edwin Chan ; Anne M. Baranger ; Paul J. Hergenrother
Journal of the American Chemical Society 2014 Volume 136(Issue 17) pp:6355-6361
Publication Date(Web):April 4, 2014
DOI:10.1021/ja5012146
A working hypothesis for the pathogenesis of myotonic dystrophy type 1 (DM1) involves the aberrant sequestration of an alternative splicing regulator, MBNL1, by expanded CUG repeats, r(CUG)exp. It has been suggested that a reversal of the myotonia and potentially other symptoms of the DM1 disease can be achieved by inhibiting the toxic MBNL1-r(CUG)exp interaction. Using rational design, we discovered an RNA-groove binding inhibitor (ligand 3) that contains two triaminotriazine units connected by a bisamidinium linker. Ligand 3 binds r(CUG)12 with a low micromolar affinity (Kd = 8 ± 2 μM) and disrupts the MBNL1-r(CUG)12 interaction in vitro (Ki = 8 ± 2 μM). In addition, ligand 3 is cell and nucleus permeable, exhibits negligible toxicity to mammalian cells, dissolves MBNL1-r(CUG)exp ribonuclear foci, and restores misregulated splicing of IR and cTNT in a DM1 cell culture model. Importantly, suppression of r(CUG)exp RNA-induced toxicity in a DM1 Drosophila model was observed after treatment with ligand 3. These results suggest ligand 3 as a lead for the treatment of DM1.
Co-reporter:Lien Nguyen;JuYeon Lee;Chun-Ho Wong ; Steven C. Zimmerman
ChemMedChem 2014 Volume 9( Issue 11) pp:
Publication Date(Web):
DOI:10.1002/cmdc.201490040
Co-reporter:Lien Nguyen;JuYeon Lee;Chun-Ho Wong ; Steven C. Zimmerman
ChemMedChem 2014 Volume 9( Issue 11) pp:2455-2462
Publication Date(Web):
DOI:10.1002/cmdc.201402095

Abstract

Myotonic dystrophy type 2 (DM2) is caused by an expansion of CCTG repeats in the zinc-finger protein gene (ZNF9). Transcribed CCUG repeats sequester muscleblind-like protein 1 (MBNL1), an important alternative splicing regulator, preventing its normal function, leading to the disease phenotype. We describe a series of ligands that disrupt the MBNL1–r(CCUG)n interaction as potential lead agents for developing DM2 therapeutics. A previously reported triaminopyrimidine–acridine conjugate was a moderate inhibitor in vitro, however it proved to be poorly water-soluble and not cell-permeable. To improve its therapeutic potential, the new set of ligands maintained the key triaminopyrimidine recognition unit but replaced the acridine intercalator with a bisamidinium groove binder. The optimized ligands exhibit low micromolar inhibition potency to MBNL1–r(CCUG)8. Importantly, the ligands are the first to show the ability to disrupt the MBNL1–r(CCUG)n foci in DM2 model cell culture and exhibit low cytotoxicity.

Co-reporter:Cyrus A. Anderson ; Amanda R. Jones ; Ellen M. Briggs ; Eric J. Novitsky ; Darrell W. Kuykendall ; Nancy R. Sottos
Journal of the American Chemical Society 2013 Volume 135(Issue 19) pp:7288-7295
Publication Date(Web):April 16, 2013
DOI:10.1021/ja4005283
Adhesion phenomena are essential to many biological processes and to synthetic adhesives and manufactured coatings and composites. Supramolecular interactions are often implicated in various adhesion mechanisms. Recently, supramolecular building blocks, such as synthetic DNA base-pair mimics, have drawn attention in the context of molecular recognition, self-assembly, and supramolecular polymers. These reversible, hydrogen-bonding interactions have been studied extensively for their adhesive capabilities at the nano- and microscale, however, much less is known about their utility for practical adhesion in macroscopic systems. Herein, we report the preparation and evaluation of supramolecular coupling agents based on high-affinity, high-fidelity quadruple hydrogen-bonding units (e.g., DAN·DeUG, Kassoc = 108 M–1 in chloroform). Macroscopic adhesion between polystyrene films and glass surfaces modified with 2,7-diamidonaphthyridine (DAN) and ureido-7-deazaguanine (DeUG) units was evaluated by mechanical testing. Structure–property relationships indicate that the designed supramolecular interaction at the nanoscale plays a key role in the observed macroscopic adhesive response. Experiments probing reversible adhesion or self-healing properties of bulk samples indicate that significant recovery of initial strength can be realized after failure but that the designed noncovalent interaction does not lead to healing during the process of adhesion loss.
Co-reporter:Yagang Zhang, Cyrus A. Anderson, and Steven C. Zimmerman
Organic Letters 2013 Volume 15(Issue 14) pp:3506-3509
Publication Date(Web):July 1, 2013
DOI:10.1021/ol401035t
Covalently linking DNA base analogues DAN, DeUG, or UPy to glass slides led to functional surfaces that could be glued together using a functionalized polystyrene displaying the complementary recognition unit. Nonspecific adhesion was minimized with fluorinated alkane (Teflon-like or Scotchgard-like) surfaces.
Co-reporter:Chun-Ho Wong and Steven C. Zimmerman  
Chemical Communications 2013 vol. 49(Issue 17) pp:1679-1695
Publication Date(Web):07 Dec 2012
DOI:10.1039/C2CC37316E
The concept of orthogonality has been applied to many areas of chemistry, ranging from wave functions to chromatography. But it was Barany and Merrifield's orthogonal protecting group strategy that paved the way for solid phase peptide syntheses, other important classes of biomaterials such as oligosaccharides and oligonucleotides, and ultimately to a term in widespread usage that is focused on chemical reactivity and binding selectivity. The orthogonal protection strategy has been extended to the development of orthogonal activation, and recently the click reaction, for streamlining organic synthesis. The click reaction and its variants are considered orthogonal as the components react together in high yield and in the presence of many other functional groups. Likewise, supramolecular building blocks can also be orthogonal, thereby enabling programmed self-assembly, a superb strategy to create complex architectures. Overall, orthogonal reactions and supramolecular interactions have dramatically improved the syntheses, the preparation of functional materials, and the self-assembly of nanoscale structures.
Co-reporter:Amin Haghighat Jahromi ; Yuan Fu ; Kali A. Miller ; Lien Nguyen ; Long M. Luu ; Anne M. Baranger
Journal of Medicinal Chemistry 2013 Volume 56(Issue 23) pp:9471-9481
Publication Date(Web):November 4, 2013
DOI:10.1021/jm400794z
An expanded CUG repeat transcript (CUGexp) is the causative agent of myotonic dystrophy type 1 (DM1) by sequestering muscleblind-like 1 protein (MBNL1), a regulator of alternative splicing. On the basis of a ligand (1) that was previously reported to be active in an in vitro assay, we present the synthesis of a small library containing 10 dimeric ligands (4–13) that differ in length, composition, and attachment point of the linking chain. The oligoamino linkers gave a greater gain in affinity for CUG RNA and were more effective when compared to oligoether linkers. The most potent in vitro ligand (9) was shown to be aqueous-soluble and both cell- and nucleus-permeable, displaying almost complete dispersion of MBNL1 ribonuclear foci in a DM1 cell model. Direct evidence for the bioactivity of 9 was observed in its ability to disperse ribonuclear foci in individual live DM1 model cells using time-lapse confocal fluorescence microscopy.
Co-reporter:Amin Haghighat Jahromi, Lien Nguyen, Yuan Fu, Kali A. Miller, Anne M. Baranger, and Steven C. Zimmerman
ACS Chemical Biology 2013 Volume 8(Issue 5) pp:1037
Publication Date(Web):March 11, 2013
DOI:10.1021/cb400046u
Myotonic dystrophy type 1 (DM1) is caused by an expanded CUG repeat (CUGexp) that sequesters muscleblind-like 1 protein (MBNL1), a protein that regulates alternative splicing. CUGexp RNA is a validated drug target for this currently untreatable disease. Herein, we develop a bioactive small molecule (1) that targets CUGexp RNA and is able to inhibit the CUGexp·MBNL1 interaction in cells that model DM1. The core of this small molecule is based on ligand 2, which was previously reported to be active in an in vitro assay. A polyamine-derivative side chain was conjugated to this core to make it aqueous-soluble and cell-penetrable. In a DM1 cell model this conjugate was found to disperse CUGexp ribonuclear foci, release MBNL1, and partially reverse the mis-splicing of the insulin receptor pre-mRNA. Direct evidence for ribonuclear foci dispersion by this ligand was obtained in a live DM1 cell model using time-lapse confocal microscopy.
Co-reporter:Si Kyung Yang
Israel Journal of Chemistry 2013 Volume 53( Issue 8) pp:511-520
Publication Date(Web):
DOI:10.1002/ijch.201300045

Abstract

Supramolecular polymer chemistry has emerged as a major research focus within polymer science, because of the potential to improve material properties, through the combination of noncovalent interactions and synthetic polymers. As a supramolecular handle, the most useful noncovalent interaction is hydrogen bonding, which has been used extensively, because of advantages such as synthetic accessibility, directionality, fidelity, and, most importantly, responsiveness to external stimuli. This review introduces recent advances in the development of hydrogen bonding modules that can be useful for creating a variety of supramolecular polymers. Furthermore, we present selected examples of hydrogen bonded supramolecular polymers from the literature, by dividing them into three categories: supramolecular polymers assembled from small molecules, and main-chain and side-chain supramolecular polymers.

Co-reporter:Si Kyung Yang
Advanced Functional Materials 2012 Volume 22( Issue 14) pp:
Publication Date(Web):
DOI:10.1002/adfm.201290083
Co-reporter:Si Kyung Yang
Advanced Functional Materials 2012 Volume 22( Issue 14) pp:3023-3028
Publication Date(Web):
DOI:10.1002/adfm.201200004

Abstract

The synthesis and photophysical properties of water-soluble, fluorescent polyglycerol-dendronized perylenediimides 1–4 are reported. The polyglycerol dendrons, which are known to be highly biocompatible, are found to confer high water-solubility on the perylenediimide in aqueous media while retaining its excellent fluorescent properties. Furthermore, intramolecular crosslinking of the polyglycerol dendrons using the ring-closing metathesis reaction not only enhances the photostability but also reduces the size of perylenediimide-cored dendrimers. The permeability of the various dendritic shells is probed using heavy metal ion quenchers and compared to non-dendritic but water-soluble perylenediimide 5.

Co-reporter:Andrew T. Zill, Kai Licha, Rainer Haag and Steven C. Zimmerman  
New Journal of Chemistry 2012 vol. 36(Issue 2) pp:419-427
Publication Date(Web):10 Oct 2011
DOI:10.1039/C1NJ20476A
Convergent syntheses of polyglycerol hyperbranched polymers containing fluorescent labels (fluorescein or perylene diimide (PDI)) at their core are presented. The hyperbranched polyglycerol (HPG) precursors were synthesized using a one step polymerization reaction wherein the initiator leaves a single reactive group for dye functionalization. For further site isolation, allylated HPG was synthesized allowing cross-linking via ring closing metathesis and subsequent dihydroxylation to produce water-soluble, fluorescent nanoparticles. The dyes produced showed improvements in photostability, water solubility, or quantum yield, depending on both the dye used and cross-linking. These fluorescent nanoparticles outperformed similar dyes that incorporated linear polyethylene glycol (PEG) polymers.
Co-reporter:Chun-Ho Wong;Dr. Stacie L. Richardson;Yen-Jun Ho;Alex M. H. Lucas; Dr. Tiziano Tuccinardi; Dr. Anne M. Baranger; Dr. Steven C. Zimmerman
ChemBioChem 2012 Volume 13( Issue 17) pp:2505-2509
Publication Date(Web):
DOI:10.1002/cbic.201200602
Co-reporter:Si Kyung Yang ; Xinghua Shi ; Seongjin Park ; Sultan Doganay ; Taekjip Ha
Journal of the American Chemical Society 2011 Volume 133(Issue 26) pp:9964-9967
Publication Date(Web):June 14, 2011
DOI:10.1021/ja2009136
Herein we report the synthesis of water-soluble polyglycerol-dendronized perylenediimides with a single reactive group that undergoes high-yielding click reactions. Single-molecule studies and target-specific biolabeling are reported, including the highly specific labeling of proteins on the surface of living bacterial and mammalian cells.
Co-reporter:Ying Li ; Taiho Park ; J. Kwansima Quansah
Journal of the American Chemical Society 2011 Volume 133(Issue 43) pp:17118-17121
Publication Date(Web):October 4, 2011
DOI:10.1021/ja2069278
A redox-responsive quadruple hydrogen-bonding module (eDAN) has been developed. The strong binding between the reduced form and its partner (DeUG) can be significantly decreased upon oxidation but restored upon subsequent reduction. This on–off switch was successfully applied to provide reversible control of macroscopic supramolecular polymer networks.
Co-reporter:Andrew Zill, Alexandra L. Rutz, Richie E. Kohman, Alaaldin M. Alkilany, Catherine J. Murphy, Hyunjoon Kong and Steven C. Zimmerman  
Chemical Communications 2011 vol. 47(Issue 4) pp:1279-1281
Publication Date(Web):22 Nov 2010
DOI:10.1039/C0CC04096G
A one-step, large-scale preparation of alkyne-containing hyper-branched polyglycerols (HPG) is reported. The HPGs undergo click reactions to organic azides allowing a range of applications.
Co-reporter:Ewelina Burakowska ; Jordan R. Quinn ; Steven C. Zimmerman ;Rainer Haag
Journal of the American Chemical Society 2009 Volume 131(Issue 30) pp:10574-10580
Publication Date(Web):July 6, 2009
DOI:10.1021/ja902597h
The ring-closing metathesis reaction of dendrimers containing allyl ether end groups is known to rigidify them significantly. Herein we report that polyallylated hyperbranched polyglycerol (HPG) 1 complexes the sodium salt of rose Bengal in chloroform solution but releases it readily to water. In contrast, extensively cross-linking 1 with Grubbs catalyst provides 2 which similarly complexes rose Bengal, but does not release it despite 12 h of shaking with water. Both 1 and 2 also complex thymol blue and exhibit the same differential complex stability when extracted with water. Neither 1 nor 2 complex Congo red sodium salt and more weakly solubilize the cesium salt of rose Bengal and thymol blue. Larger loop size cross-linked analogs HPG 5 and 6 also bind rose Bengal (RB) and thymol blue and are able to bind Congo red, but both release the dye more readily when extracted with water. In addition, a bathochromic shift is observed in the UV spectra for complex 6·RB, suggesting a changed microenvironment for the dye due to a tighter binding of the counteranion. Dihydroxylation of the alkene groups in 1, 2, 5, and 6 produced HPGs 3, 4, 7, and 8, respectively. HPGs 3 and 4 are both water-soluble, but 7 and 8 were not and could not be studied further. In water, HPG 4 solubilized less than one nonpolar guest (Nimodipine, pyrene, or Nile red) per polymer at least in part because it forms very large aggregates. Dynamic light scattering (DLS) and size exclusion chromatography (SEC) indicate aggregates with diameters of ca. 100 nm in pure water. The aggregates dissociated in high salt concentrations suggesting applications in stimuli responsive materials.
Co-reporter:Hugo C. Ong, Jonathan F. Arambula, Sreenivasa Rao Ramisetty, Anne M. Baranger and Steven C. Zimmerman  
Chemical Communications 2009 (Issue 6) pp:668-670
Publication Date(Web):08 Dec 2008
DOI:10.1039/B817733N
7-Deazaguanine (7-DeG) was developed as a hydrogen-bonding module capable of enhanced recognition of uracil (U) and thymine (T); a water-soluble derivative displayed high affinity and selectivity toward DNA and RNA duplexes containing single T- and U-bulges.
Co-reporter:Richie E. Kohman and Steven C. Zimmerman  
Chemical Communications 2009 (Issue 7) pp:794-796
Publication Date(Web):13 Jan 2009
DOI:10.1039/B818183G
Large degradable dendrimers (MW > 30 kDA) were synthesized in a divergent manner utilizing a novel 1,3,5-triazaadamantane (TAA) monomer that can degrade under acidic conditions.
Co-reporter:Andrew T. Zill
Israel Journal of Chemistry 2009 Volume 49( Issue 1) pp:71-78
Publication Date(Web):
DOI:10.1560/IJC.49.1.71

Abstract

Cored polymeric nanoparticles were prepared using an adenosine template and allylated hyperbranched polyglycerols (HPGs). The HPGs contained a single alkyne that was capable of 1,3-dipolar cycloaddition with a decaazido adenosine template to facilitate the rapid synthesis of HPGs containing a large number of allyl end-groups. Ring closing metathesis (RCM) mediated cross-linking at high dilution using a Hoveyda-Grubbs catalyst produced single polymer nanoparticles containing a single template. These particles were rendered water-soluble through treatment with osmium tetroxide and NMO co-oxidant. After hydrolytic removal of the template, the nanoparticles were tested for their ability to bind a variety of nucleosides and nucleobases and showed a preference for purine bases over pyrimidine bases. This is the first reported use of hyperbranched polymers for the synthesis of monomolecularly imprinted polymers (mMIPs) as well as the first time monomolecular imprinting has been applied to a homogeneous aqueous system.

Co-reporter:Akihito Hashidzume, Steven C. Zimmerman
Tetrahedron Letters 2009 50(19) pp: 2204-2207
Publication Date(Web):
DOI:10.1016/j.tetlet.2009.02.168
Co-reporter:Jonathan F. Arambula;Sreenivasa Rao Ramisetty;Anne M. Baranger
PNAS 2009 Volume 106 (Issue 38 ) pp:16068-16073
Publication Date(Web):2009-09-22
DOI:10.1073/pnas.0901824106
This work describes the rational design, synthesis, and study of a ligand that selectively complexes CUG repeats in RNA (and CTG repeats in DNA) with high nanomolar affinity. This sequence is considered a causative agent of myotonic dystrophy type 1 (DM1) because of its ability to sequester muscleblind-like (MBNL) proteins. Ligand 1 was synthesized in two steps from commercially available compounds, and its binding to CTG and CUG repeats in oligonucleotides studied. Isothermal titration calorimetry studies of 1 with various sequences showed a preference toward the T-T mismatch (Kd of 390 ± 80 nM) with a 13-, 169-, and 85-fold reduction in affinity toward single C-C, A-A, and G-G mismatches, respectively. Binding and Job analysis of 1 to multiple CTG step sequences revealed high affinity binding to every other T-T mismatch with negative cooperativity for proximal T-T mismatches. The affinity of 1 for a (CUG)4 step provided a Kd of 430 nM with a binding stoichiometry of 1:1. The preference for the U-U in RNA was maintained with a 6-, >143-, and >143-fold reduction in affinity toward single C-C, A-A, and G-G mismatches, respectively. Ligand 1 destabilized the complexes formed between MBNL1N and (CUG)4 and (CUG)12 with IC50 values of 52 ± 20 μM and 46 ± 7 μM, respectively, and Ki values of 6 ± 2 μM and 7 ± 1 μM, respectively. These values were only minimally altered by the addition of competitor tRNA. Ligand 1 does not destabilize the unrelated RNA-protein complexes the U1A-SL2 RNA complex and the Sex lethal-tra RNA complex. Thus, ligand 1 selectively destabilizes the MBNL1N-poly(CUG) complex.
Co-reporter:Ying Li, Yugang Bai, Nan Zheng, Yang Liu, Gretchen A. Vincil, Benjamin J. Pedretti, Jianjun Cheng and Steven C. Zimmerman
Chemical Communications 2016 - vol. 52(Issue 19) pp:NaN3784-3784
Publication Date(Web):2016/02/01
DOI:10.1039/C5CC09430E
Fluorescent, aqueous-soluble, crosslinked dendronized polyols (CDPs) are obtained through a sequential process involving ring-opening metathesis polymerization (ROMP), intra-chain ring-closing metathesis (RCM), and hydrolysis. This general strategy improves the quantum yields (QYs), brightness, and photostability of five common fluorophores whose emission wavelengths cover 150 nm. Additionally, the availability of the polymeric fluorophore to the cytosomes opens the door to applications in bioimaging and intracellular delivery.
Co-reporter:Chun-Ho Wong and Steven C. Zimmerman
Chemical Communications 2013 - vol. 49(Issue 17) pp:NaN1695-1695
Publication Date(Web):2012/12/07
DOI:10.1039/C2CC37316E
The concept of orthogonality has been applied to many areas of chemistry, ranging from wave functions to chromatography. But it was Barany and Merrifield's orthogonal protecting group strategy that paved the way for solid phase peptide syntheses, other important classes of biomaterials such as oligosaccharides and oligonucleotides, and ultimately to a term in widespread usage that is focused on chemical reactivity and binding selectivity. The orthogonal protection strategy has been extended to the development of orthogonal activation, and recently the click reaction, for streamlining organic synthesis. The click reaction and its variants are considered orthogonal as the components react together in high yield and in the presence of many other functional groups. Likewise, supramolecular building blocks can also be orthogonal, thereby enabling programmed self-assembly, a superb strategy to create complex architectures. Overall, orthogonal reactions and supramolecular interactions have dramatically improved the syntheses, the preparation of functional materials, and the self-assembly of nanoscale structures.
Co-reporter:Hugo C. Ong, Jonathan F. Arambula, Sreenivasa Rao Ramisetty, Anne M. Baranger and Steven C. Zimmerman
Chemical Communications 2009(Issue 6) pp:NaN670-670
Publication Date(Web):2008/12/08
DOI:10.1039/B817733N
7-Deazaguanine (7-DeG) was developed as a hydrogen-bonding module capable of enhanced recognition of uracil (U) and thymine (T); a water-soluble derivative displayed high affinity and selectivity toward DNA and RNA duplexes containing single T- and U-bulges.
Co-reporter:Richie E. Kohman and Steven C. Zimmerman
Chemical Communications 2009(Issue 7) pp:NaN796-796
Publication Date(Web):2009/01/13
DOI:10.1039/B818183G
Large degradable dendrimers (MW > 30 kDA) were synthesized in a divergent manner utilizing a novel 1,3,5-triazaadamantane (TAA) monomer that can degrade under acidic conditions.
Co-reporter:Andrew Zill, Alexandra L. Rutz, Richie E. Kohman, Alaaldin M. Alkilany, Catherine J. Murphy, Hyunjoon Kong and Steven C. Zimmerman
Chemical Communications 2011 - vol. 47(Issue 4) pp:NaN1281-1281
Publication Date(Web):2010/11/22
DOI:10.1039/C0CC04096G
A one-step, large-scale preparation of alkyne-containing hyper-branched polyglycerols (HPG) is reported. The HPGs undergo click reactions to organic azides allowing a range of applications.
2H-1-Benzopyran-2-one, 7-[1-(2-pyridinylmethyl)-1H-1,2,3-triazol-4-yl]-
1H-1,2,3-Triazole-1-pentanoic acid, 4-phenyl-, ethyl ester
1H-1,2,3-Triazole, 1-decyl-4-phenyl-
1H-1,2,3-Triazole, 4-(4-fluorophenyl)-1-(phenylmethyl)-
1H-1,2,3-Triazole, 4-phenyl-1-(3-phenylpropyl)-
1H-1,2,3-Triazole, 4-(4-methylphenyl)-1-(phenylmethyl)-
2H-1-Benzopyran-2-one, 7-hydroxy-3-[4-(4-methoxyphenyl)-1H-1,2,3-triazol-1-yl]-
2H-1-Benzopyran-2-one, 3-azido-7-hydroxy-
Pyridine, 2-(azidomethyl)-